TNPSC Chemistry - States of Matter
Exam Duration: 45 Mins Total Questions : 30
The temperature to which a gas must be cooled before it can be liquefied by compression is called
- (a)
Boyle's temperature
- (b)
critical temperature
- (c)
liquefaction temperature
- (d)
inversion temperature
Consider the following statements
1. When evaporation takes place, cooling takes place.
2. Evaporation takes place at all temperatures, boiling takes place only at the boiling point.
3. Evaporation is a surface phenomenon.
Which of the above is/are true?
- (a)
Only 1
- (b)
1 and 2
- (c)
2 and 3
- (d)
1,2 and 3
Assertion (A) Surface tension decreases on increasing temperature. Reason (R) Intermolecular attractive forces are comparatively smaller at higher temperatures.
- (a)
Both A and R are true and R is the correct explanation of A
- (b)
Both A and R are true, but R is not the correct explanation of A
- (c)
A is true, but R is false
- (d)
A is false, but R is true
At very low temperature, oxygen O2, freezes and forms a crystalline solid.
Which term best describe the solids?
- (a)
Covalent network
- (b)
Molecular crysals
- (c)
Metallic
- (d)
lonic
Dry ice is used for making cold-baths in laboratories by mixing with volatile organic solvents. Identify the form of dry ice the following.
- (a)
Gaseous carbon dioxide
- (b)
Liquid carbon dioxide
- (c)
Solid carbon dioxide
- (d)
Solid hydrogen oxide
Consider the following statements
1. Gaseous substances whose critical temperature are above room temperature can be liquefied by applying sufficient pressure to the gas
2. Gaseous substances whose critical temperature are below room temperature can be liquefied by the application of pressure and lowering of temperature below Tc
Select the correct alternate.
- (a)
Only 1
- (b)
Only 2
- (c)
Both 1 and 2
- (d)
None of these
At constant temperature, the product of pressure and volume of a given amount of a gas is constant. This is
- (a)
Gay-Lussac law
- (b)
Charles' law
- (c)
Boyle's law
- (d)
Pressure law
Consider the following statements
1. The rate of diffusion of liquids is higher than that of solids.
2. In the liquid state, particles move freely and have greater space between each other as compared to particles in the solid state.
Which of the statement(s) given above is/are correct?
- (a)
Only 1
- (b)
Only 2
- (c)
Both 1 and 2
- (d)
None of the above
Glasses and plastics are
- (a)
amorphous solids
- (b)
supercooled liquid
- (c)
Both (a) and (b)
- (d)
None of these
Assertion (A) All molecules of an ideal gas move the same speed.
Reason (R) There is no attraction between the molecules in an ideal gas.
- (a)
Both A and R are true and R is the correct explanation of A
- (b)
Both A and R are true, but R is not the correct explanation of A
- (c)
A is true, but R is false
- (d)
A is false, but R is true
Consider the following statements
1. Atmospheric pressure is less at the top of a mountain than at sea level.
2. Gases are much more compressible than solids and liquids.
3. When the atmospheric pressure increases, the height of the mercury column rises
Select the correct statements.
- (a)
1,2
- (b)
2,3
- (c)
1,3
- (d)
1,2,3
H2O is a liquid and H2S is a gas because
- (a)
oxygen forms stronger hydrogen bond sulphur
- (b)
oxygen is less electronegative than sulphur
- (c)
atomic radius of oxygen is less than that sulphur
- (d)
atomic radius of oxygen is greater than that of sulphur
Assertion (A) With the increase of temperature the viscosity of glycerine increases.
Reason (R) Rise of temperature increases kinetic energy of molecules.
- (a)
Both A and R are true and R is the correct explanation of A
- (b)
Both A and R are true, but R is not the correct explanation of A
- (c)
A is true, but R is false
- (d)
A is false, but R is true
At absolute zero, which one of the following is zero for a gas?
- (a)
Potential energy
- (b)
Kinetic energy
- (c)
Vibration energy
- (d)
None of the above
Which one of the following is used as an anti-freezer, which effectively depresses the freezing point of water in an automobile?
- (a)
Ethylene glycol
- (b)
Propanoic acid
- (c)
Glutamic acid
- (d)
Glycolic acid
An ideal gas is one which obeys
- (a)
Gas law
- (b)
Boyle's law
- (c)
Charles' law
- (d)
Avogadro's law
What is the term used to denote the critical temperature at which the air becomes saturated with vapour and below which the condensation is likely to begin?
- (a)
Condensation point
- (b)
Evaporation point
- (c)
Dew point
- (d)
Point of critical temperature
According to which one of the following laws it is indicated that when two or more gases react with one another, their volumes bear a simple ratio?
- (a)
Law of mass action
- (b)
Law of multiple properties
- (c)
Law of reciprocal properties
- (d)
Law of combining volumes
Assertion (A) All liquids are conductors of electricity.
Reason (R) Under the condition of low pressure and high voltage, liquids can be made conductng
- (a)
Both A and R are true and R is the correct explanation of A
- (b)
Both A and R are true, but R is not the correct explanation of A
- (c)
A is true, but R is false
- (d)
A is false, but R is true
On increasing pressure, melting point of ice
- (a)
decreases
- (b)
increases
- (c)
remains unchanged
- (d)
changes in regular manner
Consider the following statements
1. All liquids have concave meniscus
2. All liquids have convex meniscus
3. Mercury has concave and other liquids have convex meniscus
Which of the above is/are true?
- (a)
Only 1
- (b)
2 and 3
- (c)
Only 3
- (d)
None of these
Consider the following statements
1. One water molecule forms four H-bonds
2. Water has high boiling due to hydrogen bonding
3. When ice is melt, collapse of structure leads to increase in density
Which of the statements given above is/are correct?
- (a)
1,2 and 3
- (b)
1 and 3
- (c)
2 and 3
- (d)
Only 2
Consider the following statements
1Super critical CO2 (ScCO2 ) is ideally suited in food processing and production of pharmaceuticals
2. The best scientific method to test the presence of water in aliquid is use of anhydrous CuSO4
3. A great advantage of ScCO2 is that there are no noxious residues once the solvent has been allowed to evaporate
Which of the above is/are true?
- (a)
Only 1
- (b)
Only 2
- (c)
2 and 3
- (d)
1,2 and 3
Select the correct statement(s)
1. Liquid lead does not wet a solid iron surface since the interfacial tension between these two phase is quite large
2. Alloys of tin and lead are used in soldering because the interfacial tension between the liquid and solid is reduced and the liquid flows over solid surface
3. Ice has a sharp melting point whereas glass melts over a range of temperature
- (a)
Only 1
- (b)
Only 2
- (c)
2 and 3
- (d)
1,2 and 3
Amorphous materials are in fact considered as
- (a)
supercooled liquids
- (b)
supercooled solids
- (c)
covalent network
- (d)
molecular crystals
In general equation pV=nRT, V is the volume of
- (a)
n mole of a gas
- (b)
any amount of gas
- (c)
one mole of a gas
- (d)
one gram of a gas
Phase change from gas to solid is called
- (a)
sublimation
- (b)
deposition
- (c)
fusion
- (d)
vaporisation
Consider the following statements
1. The particles of nail polish remover pour on your palm, the particles gain energy from your palm or surroundings and evaporate causing the palm to feel cool
2. After a hot sunny day, people sprinkle water on the roof or open ground because the large latent heat of vaporisation of water helps to cool the hot surface
Which of the statement(s) given above is/are correct?
- (a)
Only 1
- (b)
Only 2
- (c)
1 and 2
- (d)
None of these
Consider the following statements In gaseous state
1. the molecule are very loosely packed having large empty space between them
2. molecules move very rapidly in all direction in a random manner
3. the molecules collide with one another and also with walls of the container with perfectly elastic collisions
Which of the statements given above are correct?
- (a)
1 and 2
- (b)
2 and 3
- (c)
1 and 3
- (d)
1,2 and 3
If a gas is compressed to half of its original volume of 270C, to what them should it be heated to make it occupy its original volume
- (a)
3270C
- (b)
6000C
- (c)
540C
- (d)
3000C